The following essay is reprinted with permission from The Conversation, an online publication covering the latest research.
In the wake of Roe v. Wade’s reversal, it is more important to develop more contraception options that are accessible to everyone.
Women who can get pregnant have a number effective birth control methods , including oral pills and patches, IUDs, IUDs, and sterilization. However, there are limited options for men and sperm-producing people. Both withdrawal and condoms have high success rates . Withdrawal has a failure rate of about 20%. Condoms have a failure rate of only 2% when used correctly, but that rate rises to 13% based on how people typically use them. Vasectomies have a lower failure rate than condoms, but they are minimally invasive and considered permanent contraceptives. Vasectomies and withdrawal do not protect against sexually transmitted infection.
There has not been a new form of male birth control since the introduction of the “no-scalpel vasectomy” in the 1980s. I, along with my team, have been developing male contraception methods since the 1970s. I believe that new safe, reversible and affordable contraception options can help men participate and share contraceptive responsibilities with their partners, and reduce the rate of unintended pregnancies.
Taking responsibility for family planning
A 2017 survey of 1,500 men ages 18 to 44 found that over 80% wanted to prevent their partner from getting pregnant and felt that they had shared or sole responsibility for birth control.
Men who are unhappy with condoms are more inclined to use withdrawal as a method of contraception or to not use it at all. Of those dissatisfied with condoms, however, 87% percent are interested in new methods for male contraception. This translates to an estimated 17 million men in the U.S. who are looking for new methods of contraception to prevent unintended pregnancies.
Similarly, a 2002 survey of over 9,000 men in nine countries over four continents found that over 55% would be willing to use a new method of male birth control. Importantly, a 2000 survey across three continents found that 98% of women would trust their partner to use a male birth control method.
Barriers to male contraception
Strong interest in a new male contraceptive raises the question of why there haven’t been any new male birth control methods since the ’80s.
Male contraception development has primarily been supported by governmental and nongovernmental organizations, including the World Health Organization working with academic medical centers. However, these agencies frequently do not have a drug development infrastructure comparable to pharmaceutical companies, with programs typically run by only a handful of personnel assisted by clinical research organizations. Development is further slowed down by limited financial resources.
Lack of interest from pharmaceutical companies may also play a role in deterring male contraception development, and there are a number of possible reasons the drug industry shies away from male birth control. One reason is that the cost of development is weighed against the potential market. Other reasons include uncertainties about who would dispense these drugs and unclear regulatory requirements for male contraceptive methods to receive FDA approval. If a pregnancy occurs, companies may be concerned about their liability.
New methods currently in development
Researchers currently investigate several methods of male contraception.
Hormonal methods are usually taken as a gel applied to the skin, injection to the muscle or oral pill. These methods usually contain testosterone and a hormone called progestin. Two pituitary hormones are suppressed by the progestin, which is used to suppress the function of the testes, which are the organs responsible for producing sperm. Although the testes need high levels of testosterone to make sperm for their purposes, testosterone is often included in hormonal methods to ensure that the hormone is available for other bodily functions. Counterintuitively, taking testosterone may also help suppress sperm production, because increasing circulating testosterone levels above a certain level suppresses the same two pituitary hormones. The suppression of sperm formation is further enhanced by the addition of a progestin.
The hormonal contraceptive candidate furthest along in development is currently in an ongoing second stage clinical study that has recruited over 400 couples across four continents. This trial was conducted at the Lundquist Institute by me as principal investigator. The results of the study, sponsored by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the Population Council, have so far been promising with minimal side effects, and the couples have found the gel acceptable to use.
My team and I are also developing drugs that function like both testosterone and progestin, but in a single compound. These drugs are currently being tested in early testing on humans as an oral pill or long-acting injection.
Nonhormonal methods typically involve drugs that specifically target sperm-producing organs to decrease sperm concentration or function. While nonhormonal drugs have shown efficacy on animal models, preclinical toxicology results will be required before clinical trials to prove safety, tolerability, and efficacy in humans can begin. A few of these methods are working toward first-stage clinical trials.
Another non-hormonal method is to reversibly block the vas deferens. This organ transports sperm for fertilization. Studies sponsored by the Male Contraceptive Initiative and Parsemus Foundation are testing hydrogels, a type of polymer that retains water, that block sperm from traveling through the vas deferens.
People are open to new contraceptive methods. Collaboration across the academic, government, non-profit, and pharmaceutical sectors is possible to deliver safe, reversible, accessible, and affordable birth control methods.